Plugged telltale hole



Patented May 26, 1936 AUNITED STATES .PATENT OFFICE PLUGGED TELLTALE HOLE Sam Fennelle Henry, Guntersville, Ala.

Application October 26 1 Claim.

The herewith disclosed invention relates to plugged tell tale holes, and has for its principal object a means whereby excessive corrosion `on the inside of a boiler or other pressure vessel can be instantly detected.

It is common practice in installations, where pressure vessels of any character are used, to make a periodic inspection of such vessels. At such periodic inspections it is customary to shut down the boiler or other pressure vessel and to enter said vessel through a manhole or other opening and determine, either by Visual inspection, by tapping with a hammer, or by other means, at what point the said vessel has corroded, or otherwise deteriorated, and to what extent, and particularly to what depth, the said corrosion and/or deterioration has extended. It will be obvious from the preceding discussion that such means of inspection are slow, costly, and hazardous to the inspectors, and in many other respects inefcient. It is the purpose of my invention to eliminate the difculties above referred to, by providing a plugged tell tale hole complete with a petcock, valve, or other device, such that when corrosion and/or deterioration has extended to, or beyond, a specified depth in the wall of the pressure vessel, that the defective condition, at the point in question, may be determined by simply opening the said petcock or Valve and noting whether or not any of the fluid or gaseous contents of the Vessel escapes, drips, or are otherwise expelled therefrom. It will be obvious from the further description of my device that in case deterioration and/or corrosion has occurred at any point to such a depth that the wall of the boiler or other pressure vessel thereby, that such condition will be instantly detected when the valve in the plugged tell tale hole, located at the affected point, is opened, or in case only a plug is used, when the plug is removed.

It should be noted that individuals familiar with the operation and inspection of boilers and other pressure vessels know the points at which corrosion and/or deterioration are likely to occur and as a result can so adapt, locate, and use my invention, that visual inspection of the interior of a boiler or other pressure vessel will no longer be necessary except after much longer periods of use than is now the practice.

In the accompanying drawing in which like characters of reference refer to like parts throughout the several views:

Fig. I is an oblique View of a boiler or other pressure vessel.

is weakened v 1934, serial No. 750,160

Fig. II is a sectional end view to reduced scale of a boiler or other pressure vessel showing my invention in place at one possible location.

Fig. III is a fragmentary end View of a section of the vessel shown in Figs. I and II. Said section being taken out of said vessel at any suitable point such as A-A.

Fig. IV is the preferredv form of the invention and is a fragmentary end view of a section of the vessel shown in Figs. I and II. Said section being taken out of the vessel at any suitable point such as A-A.

Fig. V is the same is Fig. III, IV or VI except that in this form valve means are not used. Inspection is performed by simply removing the plug 'l and noting any bulge, deformation or perforation of the bottom of the hole 2.

Fig. VI is a modied form of the inventionl and is a fragmentary end view of a section of the vessel shown on Figs. I and II. Said section being taken out of the vessel at any suitable point such as A-A.

Referring now more particularly to the reference numerals:

i is a boiler, or other pressure vessels, or any form of liquid uid or gaseous container in which deterioration and/or corrosion may occur. Located, at any suitable point in the wall of said vessel, is a plugged tell tale hole 2, of the character hereinafter described and shown to a larger scale in Figs. III, IV, V and VI. In these views 3 refers to the boiler wall of thickness d in which is drilled a hole 5 of such depth 6 that the vessel I would no longer be safe if the corrosion lil had reached this depth. In the preferred form of construction, as illustrated in Fig. IV, a plug l is inserted in the aforementioned hole 5, and a petcock or other form of valve 8 is inserted in said plug. If desired, no valve need be used. The inspection is, in this case, performed simply by removing the plug 1, Fig. V. In the form of the device illustrated in Fig. III the plug l is not used, but a patch 9 is welded directly over the hole 5 and the petcock, or other form of valve 8, is inserted directly into this patch. In this form, also, a removable plug 1, Fig. V, could be used in place of the Valve 8. In Fig. VI a further modified f orm of the device is illustrated. In this form of the device no auxiliary plug or patch is used, and the petcock or valve 8 is inserted directly into the hole 5, which is drilled and tapped to the proper size to receive the shank of the petcock or valve 8. I-Iere also a plug 'l could be used, as shown in Fig. V, and the valve 8 omitted. In which case the face level of the liquid contents, while in other, Y

cases it will be more expedient to locate the device higher up in the vessel, and above the surface level of the liquid contents. In the former case when excessive corrosion occurs the dangerous condition will be indicated by a fluid flow when the valve 8 is opened, or the plug 1 removed, andv in the latter case gas or steam will escape when the valve: is open thus indicating that the vessel has been corroded away, at the point in question, until the hole 5 is in direct connection with the inside 0f the vessel. It should be noted that in theI claim as appended hereto the invention is neither limited in its use to any particular type of vessel, nor to any specified location. Neither do the contents, nor the pressure, nor the lack of pressure a vessel in any way affect th breadth of the invention as covered by the attached claim.

Having thus described my invention what I claim and desire to secure by Letters Patent is- A closed unlined pressure vessel of unitary wall construction having an opening therein extending partially through the same from the exterior thereof, means for reinforcing the wall of said vessel at the point adjacent the opening l0 aforementioned, said means comprising a patch with a tapped hole formed therethrough, and

`welded to said vessel at a point such that the hole through the patch and the opening in the pressure vessel are in substantial alignment, a l5 nipple inserted in said tapped hole and a manually operable valve inserted on said nipple so that when the interior surface of the vessel adjacent the aforementioned reinforcing patch has worn or corroded away to a predetermined extent 20' v the pressure in the vessel will cause fluid to escape into the aforementioned opening` and Athus through said nipple and into said valvey thereby providing means for indicating upon a subsequent opening of said valve the presence of a 25 dangerous condition.

SAM FENN ELLE HENRYL 

